1. Field of the invention
This invention relates to a ladder leveling adapter and more particularly to an adapter having legs to be mounted on a common ladder in order to stand vertically on an uneven surface.
The present adapter is particularly designed to be adjusted quickly, with precision, and be completely reliable to support heavy weights climbing the ladder even beyond the expected capacity.
2. Prior art
A plurality of ladder leveling attachments have been contemplated which require a toothed arrangement such as in U.S. Pat. Nos. 2,127,884 3,083,788 and 3,882,966 and Canadian Pat. Nos. 138,945 and 468,425. The manufacturing of such a design is relatively expensive considering that a toothed surface requires an elaborate mode of production. Furthermore, toothed surfaces provide a leveling adaptation which is not continuous and accordingly, is not suitable when a precise adjustment of the legs on the side rails is needed. This is particularly the case when the ladder is long and a small difference in level causes the ladder to tilt excessively.
U.S. Pat. No. 3,406,785 discloses a ladder supporting surface compensating means making use of a continuous sliding rod on the side of the ladder. This compensating means is particularly adapted for a wooden ladder wherein the attachment is bolted to the ladder and the tightening means frictionally engages the rod. Such an arrangement substantially compares to the one described in Canadian Pat. No. 629,827.
An elaborate leveling device is described in U.S. Pat. No. 5,044,468. Hydraulic pistons are mounted on each side of the ladder and are adapted to selectively adjust according to the height of the ground on which they stand.
None of the above ladder leveling device are concerned with the production of inexpensive adapters which can be raised continuously and be securely locked quickly.